Drug delivery system cationic polymers

Topical spermicides such as nonoxynol-9 (N9) and benzalkonium chloride act on sperm membranes through a detergent effect, namely, hydrophobe-hydrophobe interaction between the active and substrate (spermatozoa). The idea was to optimize the cationic/hydrophobic polymer in the drug delivery system so epithelial cells were protected without sacrificing the drug s spermicidal activity. One of the questions that needed to be answered in designing an optimum cationic/hydrophobe modified polymer was the effect of the hydrophobe on the drug activity (N9 initially, and other actives subsequently). 

Loftsson, T., Leeves, N., Sigurjonsdottir, J. F., Sigurosson, H. H., and Masson, M. 2001. Sustained drug delivery system based on a cationic polymer and an anionic drug/cyclodextrin corfiftemazie. 

The preparation of cationic lipid nanoparticles containing a lipophilic drug and its encapsulation into an anionic polymer network by ionic interaction for use as an oral drug delivery system are reported. The lipid nanoparticles serve as the core of a capsule, which is produced from a semi-interpenetrating polymer network of sodium alginate and hydroxypropylmethylcellulose. Satisfactory drug release is achieved through control of the composition of the capsule material and environmental pH. 14 refs. 

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